One thing you should know, if they’re out of town- they dont have adequate supervision, no matter how strict the Yeshiva is. Thats why, you have to know your son, does he need that extra supervision?
That’s not to say that you shouldnt send him.
Personally, for the right boys, it’s very healthy to be out of town. It teaches them social and organizational skills, independence, and more. My husband and all my brothers, and in laws learned in Eretz Yisroel, and they couldnt have had a better experience Baruch Hashem. But again, for others- it just gives them too much independence and it does not bring them too much good.
It’s a big decision, and whatever you do- Hatzlacha Rabbah!